High voltage supplies



J. P. SMITH HIGH VOLTAGE SUPPLIES Feb. 26, 1957 Filed March 25, 1954 2 Sheets-Sheet l Joy v 1? JTTORNLY Feb. 26, 1957 I J. P. SMITH 2,783,413

7 HIGH VOLTAGE SUPPLIES Filed March 25, 1954 2 Sheets-Sheet 2 05mm W lawn/m a; F 7 l 15% d/ec'a/rs V i/Wi! 14,9 v hh' M T I T T ffi e I I r r 5 F, g'; 7 a. P: 7 F/LTEE F/LTEE INVE N TOR.

ATTORNEY 2,783,413 7 HIGH voLrAcut surrrms John P. Smith, Princeton, N.- J., assignor' to Radio Corporation of America, acorporafion of Delaware Application March 23, 1954, Serial No. 418,114 8 Claims. c1. SIS-16) This invention relates generally to voltage supplies and more particularly to voltage supplies of the type suitable for use to satisfy the high voltage requirements of a cathode ray tube.

It has been more or lessconventional in the monochrome television art to obtain the high voltages required by a receivers kin'escope from a pulse type supply, developing the high voltages v'ia rectification of the transient flyback pulses appearing across the receivers horizontal output transformer during retrace periods of the line scanning cycle. Direct adaptationof such supplies to use in color television receivers has usually been found not to be feasible, for withcolor kinesc'opes of the-types presently contemplated, the high voltage requirements are generally ofgreater magnitude; more criticalas to regulation, and over all pr ese'nt'a significant-ly more complex problem than the monochrome kinescope supplies.

As an example, the! high voltage requirements of a typical color k'iriescope of the s'o-ealled focus mask type may be considered. The focusmask type of color kinescope may generally be described as a type of cathode ray tube employing a beamtarget assembly including a multi-color phosphor target and an electron lens system in which a pair of grill or mask electrodes cooperate with said phosphor target as lens elements. A detailed disclosure of, and explanation of, tubes of this type is contained in the co-p'endin-g application of Edward G. Ramberg, Ser. No; 277,182,- filedMarch 18, 1952, and entitled Cathode Ray Tubes of the Lenticular Grill Variety, now U. S. Patent 2,728,024, issued December 20, 1955. Without entering into a detailed analysis of the theory and manner of operation of such tubes, the purposes of the present explanation maybe served by noting that a typical tube of this type has the following high voltage requirements: a voltage of approximately 20-kv., and a voltage'betweeh approximately 13 and 15 kv., for elements of the target lens system including the phosphor target, the two grill electrodes and the ultor electrode; a static beam convergence voltage of approximately 9 to 11 kv.; and-a focusing voltage of approximately 2 to 4 kv. If the supply is to be applicable to other than one predetermined "kinescope, means for adjusting over the 13 to 15 kv. range, 9 to 11 kv. range, etc. must be provided. Each of .the target lens element voltages must be regulated to approximately 1%, and if one varies the other should vary such-as to maintain a predetermined ratio therebetween. Similarly the focus and convergence voltages should each be comparably regulated and should ""track with the target voltage variations so as to maintain an essentially constant ratio therewith. Typical maximum currents drawh by the various tube elements at the aforesaid voltages may be of the order of 300 microamper'es, with the exception of a negligible current demand on the convergence voltage source.

It will be appreciated that mere adaptatienrof the connited States Patent G ventional monochromekinescopes highvoltag'esupply to satisfy the rigid requirements set forth above is virtually impossible. Hence, it is a primary purpose of the present invention to provide a novel high voltage supply which may serve as a practical solutionto the problem of deriving operating voltages for cathode ray tube elements, under such requirements as indicated above, from a pulse source, such as the receivers horizontal output transformer, with a minimum of wasted power and with a minimum interference with the desired operation of the deflection system.

It is therefore a primary object of the present invention to provide novel and improved voltage supplies.

It is a further object of the present invention to provide a novel high voltage supply, which may be utilized to satisfy the high voltage requirements of acolor kinescope with minimum power losses and with satisfactory regulation.

In accordance with an embodiment of the present invention which achieves the aforesaid objects, the two voltages which are required for target elements, each of which must be well regulated, and which must be maintained in an essentially constant rat-iorelationship are derived in a novel manner. The maximum flyback pulse potential available in the horizontal outputtransformer is rectified to obtain the lower of these two voltages. An adjustable flyback pulse potential of a lower order is derived from the output transformer through use of an adjustable inductive divider, rectifier, and added to the first rectified voltage to provide the higher target voltage. A shunt regulator tube is associated with the higher target voltage output, and maintains it essentially constant whereby the aforesaid inductive divider adjustment effectively achieves changes in the lower target voltage. The static convergence voltage is derived from a bleeder shunting the regulated higher target voltage output, or, alternatively, the lower target voltage output. A separate focus rectifier and associated regulator provide the desired focus voltage. In combination, the aforesaid use of the inductive divider, the use of a modified voltage doubler wherein the voltage derived from the inductive divider is combined with the lower target voltage to obtain the higher target voltage, the use of a single regulator tube to regulate both target voltages and the convergence voltage, etc. provides a practical solution to the problems set forth without an excess of wasted power, an excessive drain on the deflection transformer, or anexcessive tube complement. In accordance with other embodiments of the present inven tion, various modifications of the basic supply described above are proposed such as the use of an inductive multiplier instead ofthe inductive divider, the combination of regulator reference voltage derivation and convergence voltage derivation in a common means, the additional use of an inductive divider or multiplier in the separate focus voltage derivation whereby the focus regulator tube may be eliminated, et al., and these modifications and improvements will be specifically explained in the detailed description that follows.

Objects and advantages of the present invention other than those discussed above will be readily apparent to those skilled in the art upon a reading of the following detailed description and an inspection of the accompanying drawings in which:

Figure 1 illustrates schematically a high voltage supply in accordance with an embodiment of the present invention.

Figures 2 and 3 illustrate schematically several modifications of the supply of Figure l which may be effected in accordance with" other embodiments of the present invention.

Figure 4 illustrates in block and schematic form the use of a highvoltage supply, ofthe character illustrated in the preceding figures, in a color television receiver to satisfy the high voltage requirements of the receivers' color kinescope.

Figures 5, 6 and 7 illustrate schematically various systems of application of high voltages developed by the supply of Figure 4 to elements of the target assembly of the color kinescope which the supply serves.

Referring more specifically to Figure 1, a high voltage supply 14 in accordance with an embodiment of the present invention is illustrated in association with a portion of the horizontal deflection circuits of a typical cathode ray tube system. A horizontal output tube 11 provides a horizontal yoke (not illustrated) with suitable sawtooth current scanning waves via an output transformer 13, illustrated as being of the conventional autotransformer type. The driving connection of output tube 11 to the transformer 13 is illustrated as being at an intermediate point e, while the yoke connections are illustrated at lower potential terminals a and b on the transformer 13, the conventional damper connection being indicated at point intermediate points b and e. Details of components and circuitry conventionally associated with yoke circuits, such as width and linearity controls, centering circuits, etc. have not been illustrated for the sake of simplifying the drawing.

The illustrated high voltage supply 14, it will be noted in the following description, provides a set of output voltages of the general ranges indicated previously, viz. a pair of very high voltages, V and V2, the latter lower voltage being adjustable over a limited range and maintained in a substantially constant ratio to the higher voltage V when once adjusted; an intermediate voltage Vc adjustable over a predetermined intermediate range; and a relatively lower voltage VF, also adjustable over a predetermined limited range, the lower voltages VF and V0 also being adapted to track with variations in the highest supply voltage V1. 7

The derivation of voltages V1 and V2 from the transient fiyback pulses occurring in the normal operation of the illustrated deflection output circuit will be noted to in volve the use of a modified voltage doubler circuit and an adjustable inductive divider. The circuitry and operation of this novel combination shall now be briefly explained. The anode of a first rectifier, diode 15, is connected to the high potential terminal of the output transformer 13, while the cathode of diode 15 is coupled to a point of reference potential (ground in the illustrative embodiment) via a capacitor 17. Thus, the steppedup flyback pulses appearing at terminal 1 are rectified in diode 15 to develop a first D.-C. potential across ca pacitor 17. Output terminal V2 of the supply 14 is connected to point i, the diode side of capacitor 17 An adjustable inductive divider 21 is connected across an intermediate portion of the windings of the autotransformer 13. In the specific illustration, the divider 21 is connected between the driver connection point e and a lower potential point d on the transformer 13. The operation of the adjustable inductive divider 21 in obtaining an adjustable pulse potential from the transformer 13 will be readily appreciated by those skilled in the art. Use of an inductive voltage divider in obtaining an adjustable focus voltage for an electrostatically focused cathode ray tube is disclosed in U. S. Patent 2,588,659, Wallace A. Pond, issued March 11, 1952. The operation herein may be'summed up briefly as follows: the inductance 21, tapped at its center g (or some other desired intermedeiate point), is provided with means, such as a variable core, for varying the ratio of the inductances of the two sections of inductance 21 on either side of the tapped point g. The potential derived from tap g of cours varies with such ratio adjustment. It may be noted that it is usually desirable (to minimize effects on deflection) to design the inductance 21 so that the movement of the core has as great an efiect aspossible on the ratio of the inductances of the two parts of the in- 2,783,418 I I v ,l

ductance 21 and as small an effect as possible on the total inductance of inductance 21.

A capacitor 22 couples the adjustable pulse potential point g to a point h, at the cathode of a coupling diode 23 having its anode coupled to the previously mentioned point j. The diode 23 serves the purpose of providing a low impedance path for the D.-C. potential developed across capacitor 17, while presenting a high A.-C. impedance to the pulses passed by capacitor 22. As disclosed in the co-pending application of Bernard V. Vonderschmitt, Ser. No. 416,186, filed March 15, 1954, and entitled High Voltage Supply, an inductive choke having the desired low D.-C. impedance and high A.-C. impedance may be substituted for the diode 23 in performing the coupling action. Due to the coupling action of diode 23 (or its substitute), the D.-C. potential at point j also is impressed across capacitor 22, and thus appears as added to the adjustable pulse potential derived from point g at point h. V

A second rectifier, diode 25, has its anode connected to point It and its cathode connected to point k, a capacitor 19 being coupled between the latter point and point j. The diode 25 rectifies the augmented potential appearing at point h, and there is thus developed across capacitor 19 a D.-C. potential which corresponds to the dilference between the rectified output of diode 15 and the rectified output of diode 25, i. e. a D.-C. potential corresponding in magnitude to the adjustable pulse potential derived at point g. The output terminal V1, connected to point k, sees the potentials across capacitors 17 and 19 in series and thus derives an output voltage corresponding to their sum.

To maintain the V voltage output substantially constant a conventional regulator 27, illustrated as a triode, is efiectively shunted across this output. The reference, sampling, or control voltage applied to the grid of the regulator 27 to effect its regulating operation is illustrated as being derived from a resistive voltage divider, also shunted across this output and comprising tapped resistance 29 adjustably connected to potentiometer 31. An-.

other resistive voltage divider 33 is also shown in Figure 1 as shunted across the V1 voltage output to provide a potentiometer, the adjustable tap of which is connected to the output terminal Vc of the supply 14.

A separate rectifying system for deriving the adjustable VF voltage is also included in the supply 14. A third rectifier, diode 37, has its anode connected to a point on transformer 13 of pulse potential corresponding approximately to the maximum Vn voltage desired, the point of connection in the illustrative embodiment being the aforementioned point d. A capacitor 39 is coupled between the cathode of diode 37 and ground, and the rectifying action of diode 37 develops a D.-C. potential of appropriate magnitude across capacitor 39. This D.-C. voltage is applied via a resistor 41 to the output terminal VF of the supply 14. As in the V1 output arrangement, a shunt regulator tube, triode 47, and associated sampling divider 43, 45 are provided across the VF voltage output to maintain this voltage output essentially constant at its adjusted value, determined by the setting of the tap connection of resistance 43 to potentiometer 45.

In operation, the tap connection of resistance 29 to potentiometer 31 is set to obtain the desired control voltage for regulator 27 whereby the predetermined V1 output is developed at terminal V1. Adjustment of the inductive divider 21 to change the DC. voltage developed across capacitor 19 will have substantially no effect on the voltage appearing at output terminal V1 due to the action of regulator, 27. The efiect, however, will be noted with respect to the voltage appearing at output terminal V2. That is, as the D.-C. voltage appearing across capacitor 19 is increased, the voltage developed across capacitor 17 and appearing at terminal V2 will be correspondingly pushed down, since their sum is eflectively fixed. In-

ductive divider 21 thus provides the requisite means for adjusting the output voltage V2 over its desired range. Adjustment of the output voltage Vc over its desired intermediate range is simply effected by varying its tap connection to resistive divider 33. Similarly, by controlling regulator 47s reference voltage via tap adjustment on potentiometer 45, the current drawn through resistor 41 may be adjusted to vary the voltage appearing at terminal VF over the appropriate range therefor.

Various modifications of the details of the circuitry shown in Figure 1 may be conveniently made without departing from the scope of the present invention. Several of these modifications are illustrated in Figures 2 and 3. In Figure 2 the use of an adjustable inductive multiplier 21' in place of the inductive divider 21 of Figure 1 is demonstrated. The inductive multiplier 21 may be similar to the inductive divider 21 in comprising a pair of inductive sections and means, such as an adjustable core, for varying the coupling therehetween'. The circuit connections, differ however, in that only one of the sections is shunted across the a'e portion of the output transformer 13, whilethe remaining section is connected in series with the first section, capacitor 22, and terminal h. By virtue of these modified connections an ad justable step-up of the pulse potential derived from the transformer 13 is provided. This manner of connection may prove more desirable than the balanced inductive divider of Figure 1 in such circumstances as where the range of adjustment desired for output voltage V2 would otherwise dictate tapping of the output. transformer 13 at a relatively inaccessible point thereon. The use of such an inductive multiplier in deriving an adjustable potential from a transformer is disclosed in the co-pending application of Bernard V. Vonderschmitt, Serial No. 416,050, filed March 15, 1954, and entitled Adjustable Voltage Supplies.

The embodiment of the invention shown in Figure 2 also illustrates a modification of the VF supply portion illustrated in Figure 1 whereby the VF regulator 47 and associated components may be dispensed with. As illustrated, this modification comprises the use of another adjustable inductive divider 51 for providing the desired VF changes. The excellent regulation obtained through use of the inductive divider essentially eliminates the necessity of providing the shunt regulation of the VF output.

In the embodiment of the invention illustrated in Fig ure 3 a single resistive voltage divider 30 serves to pro vide both the reference voltage for the control grid of regulator 27 and the adjustable Vc output voltage. The single divider 31 thus supplants the two output shunting dividers 33 and 29, 31 of Figure 1. It may also be noted that in Figure 3, the dual purpose divider 30 is connected between the lower potential point i and ground, rather than between the high potential point k and ground, as were the dividers in Figure 1 which it supplants. In addition to reducing power losses in the divider, the connection of the divider 30 to the lower potential point 1' may be preferable over connection to point k in that the voltage drops in the rectifiers 15 and 25 are regulated out to a greater extent.

In Figure 4, a high voltage supply 14 of the character illustrated in the preceding figures is shown in the setting of a color television receiver, wherein the supply 14 serves to provide the high voltages required for the operation of the color image reproducer, a color kinescope 140. The illustrated receiver is generally representative of presently contemplated color receivers for a simultaneous subcarrier type color television system in accordance with the revised FCC color standards, and is in general accord with the principles and apparatus discussed in the article entitled Principles and Development of Color Television Systems, by G. H. Brown and D. G. C. Luck appearing in the June 1953 issue of the RCA Review. Carrier wa'ves modulated by a composite color picture signal are illustrated as being received by conventional signal receiving apparatus 111, which may include the usual R. F. tuner, converting apparatus, 1. F. amplifier, signal detector, etc. The video frequency signals recovered from the modulated carrier in the receiving apparatus 111 are amplified in the video amplifier 113. Synchronizing information is derived from the recovered signals in the sync separator 115 and utilized to synchronously control the receivers subcarrier drive apparatus 117, to control the generation of scanning waves in the vertical deflection circuits 119, and control the generation of horizontal frequency sawtooth voltage waves in the horizontal sawtooth wave generator 121.

Respective color mixture signals (e. g. narrow band EQ signals and wider band Er signals, discussed in detail in the aforementioned article) are recovered from the video signal output of amplifier 113 in respective color demodulator channels which include bandpass filters and 127 of respectively appropriate passbands, synchronous demodulators 131 and 1 33 receiving respectively appropriate phases of the output of the subcarrier drive apparatus 117, and low pass filters 135 and 137 having the respectively appropriate narrow and wider responses. The receiver is also provided with a brightness channel, including a low pass filter 136 having the desired wide band response, through which the broad band monochrome portion of the composite picture signal may pass. The outputs of the brightness channel and two color channels are suitably combined in the matrixing circuits 139 of the receiver to obtain the simultaneous color signals which may be aplied to appropriate beam control elements of the color image reproducer 140.

In Figure 4, the color image reproducer 140 is illustrated schematically as a color kines'cope of the so-called focus-mask type, as described in the aforementioned copending Ramberg application, and referred to as being of the lenticular grill variety. In the Ramberg application the inclusion of an auxiliary grill in the target assembly in addition to the so-called focus grill is disclosed.

It may be noted that the Ramberg target assembly in operation may be said to comprise an electron lens system consisting of one set or array of converging lenses and one array of diverging lenses. An advantage of use of the Ramberg target assembly is found in the efficient utilization of the scanning beam, or beams, without color dilution resulting from the return of high velocity back scattered electrons to the fluorescent screen or from the acceleration of low velocity secondary electrons from other elements in the tube. As discussed in the Ramberg application, the phosphor arrangement on .the target screen may be of the so-called line or dot varieties. The Ramberg application also discloses various systems of grill arrangement and potential relationships between the target assembly elements, several of which are specifically considered in the present application.

In the schematic representation of color kinescope 140, three electron guns are shown for developing three scanning beams. (Alternative operation with a single gun and scanning beam is also discussed in the Ramberg application.) Each of the electron gun structures is illustrated as including a thermionic cathode 141, a control grid 143, a first anode or accelerating electrode 145, and a focusing electrode 147. A common convergence anode 1 19 is provided for all three beams. The electron gun structures may be of the general type disclosed in the co-pending application of Hannah C. Moodey, Ser. No. 295,225, filed June 24, 1952, a continuation-in-part of Ser. No. 166,416, filed June 6, 1950, now abandoned. The multi-beam convergence problem in a tube of this type is quite similar to the multi-beam convergence problem encountered in color kinescopes of the shadow-malsk type. Thus, the beam convergence circuits 156, which are illustrated as being responsive to waves derived from the vertical and horizontal deflection circuits of the re ceiver and developing therefrom suitable convergence waveforms for application to the convergence anode 149, may be in accord with the principles and apparatus disclosed in the article entitled Deflection and Convergence in Color Kinescopes by Albert W. Friend appearing in the October 1951 issue of the Proceedings of the I. R. B. As discussed in the aforesaid article the convergence apparatus may alternatively be of an electromagnetic form. Reference may be made to the co-pending application of Hunter C. Goodrich, entitled Electromagnetic Beam Systems for Tri-color Kinescopes, Ser. No. 322,653, filed November 26, 1952, now U. S. Patent No. 2,707,248, issued April 26, 1955, and to the co-pending application of Albert M. Morrell, Ser. No. 364,041, filed November 25, 1953, now U. S. Patent No. 2,752,520, issued June 26, 1956, for a disclosure of desirable forms of such electromagnetic convergence apparatus. In operation, the need for correcting beam trajectories due to alignment errors or other causes may require the use of such auxiliary components as so-called color purity coils and beam alignment magnets, which components are discussed in the aforementioned Friend article. Reference may be made to the co-pending application of Albert M. Morrell, Ser. No. 383,340, filed September 30, 1953, and to the co-pending application of M. Obert, Ser. No. 405,445, filed January 21, 1954, now U. S. Patent No. 2,769,110, issued October 30, 1956, for a disclosure of suitable forms for such beam alignment magnets.

The kinescope 140 is provided, as is conventional, with a so-called ultor electrode 150, which may take the usual form of a conductive coating on the inner surface of the kinescope envelope extending from the vicinity of the convergence anode 149 to the beam target structure 151. Where the flared portion of the kinescope envelope is of metal, the conductive coating need only extend forward sufliciently to make electrical contact with the metal flared portion.

Common deflection of the three beams to trace a scanning raster on the target structure 151-is achieved through use of a deflection yoke 153, which is provided with appropriately disposed horizontal and vertical deflection windings. The yoke 153 is illustrated as having vertical yoke terminals VV, to which field frequency scanning waves developed in the vertical deflection circuits 119 are applied. The horizontal yoke terminals H-H derive line frequency scanning waves from the horizontal output stage 161, the latter being driven by sawtooth waves from generator 121. The horizontal output stage 161 may be of the general character illustrated by the combination of output tube 11 and output transformer 13 of Figure 1.

The high voltage supply 14 is illustrated as deriving its input energy from the horizontal output stage 161, such operation being more specifically illustrated in the preceding figures. In the example illustrated by Figure 4, the four output voltages V2, V1, V and Vs of the supply 14 are utilized in the following manner: The VF terminal of the supply 14 is coupled to the focus electrodes 147 of the three electron guns to supply the desired adjustable focusing voltage thereto; the V0 output terminal of the supply 14 is coupled to the convergence anode 149 to supply the requisite adjustable static convergence voltage thereto; the V1 output terminal of the supply 14 is coupled to the auxiliary grill GA of the target assembly 151 to supply the higher target element voltage thereto; and the V2 output terminal of supply 14 is coupled to the focusing grill GF and the conductive phosphor target screen PT of the target assembly 151, and to the ultor electrode 150, to supply the lower target element voltage thereto.

As previously discussed, the aforementioned Ramberg application discloses a variety of grill arrangements and target voltage relationships. In Figure 4 the illustrated grill arrangement is that in which the auxiliary grill GA is nearest to the guns, and the focus grill G1 is disposed between the auxiliary grill GA and the phosphor target screen PT. Also, Figure 4 illustrates a target voltage relationship in which the ultor 150, the focus grill G1" and the phosphor target screen PT are all tied to the same potential V2, which is lower than the potential applied to the auxiliary grill GA. In Figure 5, a different manner of utilizing the target element voltages developed by supply 14 for the same grill arrangement is shown. In Figure 5, the auxiliary grill GA and the ultor electrode are both tied to the higher potential terminal V1, while the focusing grill GF and the phosphor target screen PT are both tied to the lower potential terminal V2.

In Figures 6 and 7 the alternative grill arrangement in which the focusing grill GF is positioned nearest to the electron guns, and the auxiliary grill GA is interpositioned between the focusing grill and the phosphor target screen PT, is shown. In Figure 6 the focus grill Gr, the phosphor target screen PT and the ultor electrode 150 are tied to terminal V2, and the auxiliary grill GA is tied to terminal V1. In Figure 7, the focus grill GF and the ultor electrode 150 are both tied to the lower potential terminal V2, while the auxiliary grill GA and the screen PT are both tied to the higher potential terminal V1.

The additional Figures 5, 6 and 7 discussed above have been presented to demonstrate the variety of possible uses for the voltages developed in a supply 14, of the novel character previously described, in different systems of operation of the focus mask tube 140. It may be noted that the grill arrangement and potential relationships illustrated in Figures 5, 6 and 7 of the present description correspond respectively to those shown in Figures 4, 5 and 6 of the aforementioned Ramberg application. In all of the examples of use discussed above, there are certain common requirements which the supply 14 must satisfy. It is desirable for proper tube operation that the V1, V2- and VF voltage outputs be each regulated to 1%, or better. It is additionally requisite that the ratio between the two target voltages V1 and V2 should remain within 1%, or better, after desired adjustment of the V2 value. It is similarly desirable that the focusing voltage VF and the convergence voltage Vo similarly track with variations in the regulated V1 output. It has been demonstrated that supplies in accordance with the novel features disclosed in Figures 1, 2 and 3 are capable of satisfying the above requirements.

It may be noted that the modification discussed with respect to Figure 3, namely, the connection of the sampling bleeder to a point 1' of V2 output potential, results in an improvement in the regulation performance of the supply under circumstances of tube operation where more current is drawn from the lower potential V2 source than from the higher potential V1 source. If the particular system of tube operation utilized results in more current being drawn from the V1 source, the connection 'of the sampling divider (whether also serving as the convergence divider or not) to a point k of V1 output potential would probably be preferable.

While a supply in accordance with the present invention has been shown and described with respect to satisfying high voltage requirements of a particular type color kinescope, it will be readily appreciated that various novel features of the present invention are applicable to use with color kinescopes of other types, and to use in supplies for various other purposes.

Having thus described my invention, what is claimed 1, In a cathode ray tube system including a periodically pulsed transformer having a high pulse potential terminal and a plurality of different intermediate pulse potential terminals, a high voltage supply comprising in combination inductive means coupled between a pair of said intermediate potential terminals for deriving an adjustable intermediate pulse potential, means coupled to said high potential terminal for rectifying said high pulse potential, at first output terminal coupled to said rectifying means, charge storage means, means for impressing said derived adjustable pulse potential on said charge storage means, means for additionally impressing said rectified high pulse potential on said charge storage means, additional means for rectifying the potentials impressed on said charge storage means, a capacitor coupled between said first and said additional rectifying means, a second output terminal, means for applying the sum of said recified high pulse potential and the potential developed across said capacitor to said second output terminal, and voltage regulating means coupled to said second output terminal for maintaining the sum potential supplied to said second output terminal essentially constant whereby changes in the adjustable pulse potential derived by said inductive means effect inverse changes of corresponding magnitude in the rectified high pulse potential supplied to said first output terminal.

2. A high voltage supply in accordance with claim 1 wherein said voltage regulating means is responsive to variations in the potential applied to said first output terminal.

3. In a cathode ray tube system including a deflection wave transformer having a high potential terminal and a plurality of different intermediate potential terminals, and requiring a pair of relatively high target element voltages, means for supplying said pair of target voltages comprising in combination a pair of output terminals, a first rectifier, a first capacitor, means for coupling said first rectifier and said first capacitor in series between said high potential terminal and a point of reference potential, an inductance comprising a pair of inductance sections in series and including means for adjusting the inductance ratio between said inductance sections, means for coupling at least one of said inductance sections between a pair of said intermediate potential terminals of said transformer, a second capacitor connected in series with said first capacitor and one of said pair of output terminals, a second rectifier, a third capacitor, means for connecting said third capacitor and said second rectifier in series between a point on said inductance and said one output terminal, D.-C. coupling means connected between the point of serial connection between said first and second capacitors and the point of serial connection between said third capacitor and said second rectifier, and means for connecting the other of said output terminals to said point of serial connection between said first and second capacitors.

4. Apparatus in accordance with claim 3 wherein both of said series connected inductance sections are connected between said pair of intermediate potential terminals, and wherein said connecting point on said inductance is the point of serial connection between said inductance sections.

5. In a color television receiver including a color kinescope comprising a focus electrode, a convergence electrode, and a plurality of target electrodes, a high voltage supply for developing target voltages for respectively difierent ones of said target electrodes, comprising in combination a transformer, means for deriving a 10 first unidirectional potential from said transformer, means for deriving a second unidirectional potential proportional to the sum of said first unidirectional potential and another adjustably derived potential, voltage regulating means shunting the output of said second unidirectional potential deriving means, said regulating tmeans maintaining said sum essentially constant, and

means for deriving a respectively different one of said target voltages from the output of each of said pair of unidirectional potential deriving means.

6. A high voltage supply in accordance with claim 5 also developing a static convergence voltage for said convergence electrode, said supply including voltage dividing means shunting the output of one of said pair of potential deriving means, and means for deriving said convergence voltage from said voltage dividing means.

7. A high voltage supply in accordance with claim 5 also developing a focusing voltage for said focus electrode, said supply including a third unidirectional potential deriving means coupled to said transformer, additional voltage regulating means shunting the output of said third potential deriving means, and means for utilizing the regulated output of said third unidirectional potential deriving means as said focus voltage.

8. In a cathode ray tube system requiring a pair of relatively high operating voltages, one of said operating voltages being adjustable relative to the other, a high voltage supply comprising in combination a transformer having a high potential terminal and a plurality of intermediate potential terminals, a first rectifier having input and output electrodes, means for coupling said first rectifier input electrode to said high potential terminal for developing a first unidirectional potential at said first rectifier output electrode, an adjustable inductive voltage divider having a pair of input terminals and an output terminal, said inductive divider input terminals being connected to a pair of said intermediate potential terminals of said transformer, a second rectifier having input and output electrodes, means for capacitively coupling said second rectifier input electrode to said inductive divider output terminal, a capacitor coupled between the output electrodes of said first and second rectifiers, means for connecting said first rectifier output electrode to said second rectifier input electrode, said conneoting means appearing as a relatively low impedance with respect to the output of said first rectifier and as a relatively high impedance with respect to the output of said inductive voltage divider, voltage regulating means connected between said second rectifier output electrode and a point of reference potential, means for deriving said adjustable operating voltage from said first rectifier output electrode, and means for deriving the other of said operating voltages from said second rectifier output electrode.

References Cited in the file of this patent UNITED STATES PATENTS 2,588,659 Pond Mar. 11, 1952 2,628,327 Vilkomerson Feb. 10, 1953 2,643,352 Parker June 23, 1953 2,679,614 Friend May 25, 1954 

